Definition of "leitmotif"

In Wagner's operas, especially his cycle of four operas known collectively as the Ring cycle, the leitmotif did not simply label or point to one particular character or object but rather conjured up a realm of ideas.

2014, Michael Slowik, After the Silents, Columbia University Press, page 14

People have pointed out the influence of Wagner’s music on my work. Certainly I do not disclaim this influence. In particular, I followed Wagner in the use of the leitmotif, which I carried over into the work of language.

1953 January, Thomas E. Mann, “The Making of "The Magic Mountain"”, in The Atlantic‎

If one looks for a pattern in the political life of John Connally, one finds a leitmotif of scandals which threatened but never destroyed his career.

1975 October 27, Aaron Latham, “John Connally on the Comeback Road”, in New York, volume 8, number 43, page 48

Mann's adaption of Wagner's technique and its development throughout his writing is analysed, including how Mann uses the leitmotif in a naturalistic, characterising and mechanical sense in Buddenbrooks, attaching it to persons and situations as etiquettes.

2009, David Gallagher, Metamorphosis, Rodopi, page 183

Such language about an American president from a European ally would have been unthinkable before Mr. Trump made outrage the leitmotif of his presidency, along with an assault on truth.

2021 January 19, Roger Cohen, “Trump Bequeaths Biden an Upended World”, in The New York Times‎